diff --git a/.gitmodules b/.gitmodules
index 7fc2686..50bd522 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "vendor/json"]
 	path = vendor/json
 	url = https://github.com/nlohmann/json
+[submodule "vendor/zlib"]
+	path = vendor/zlib
+	url = https://github.com/madler/zlib
diff --git a/CMakeLists.txt b/CMakeLists.txt
index c931486..f4aefb6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -76,7 +76,7 @@ add_executable(dbd-unlocker ${UNLOCKER_SOURCES})
 string(RANDOM LENGTH 12 ALPHABET "abcdefghijklmnopqrstuvwxyz0123456789" RANDOM_EXE_NAME)
 set_target_properties(dbd-unlocker PROPERTIES OUTPUT_NAME "${RANDOM_EXE_NAME}")
 
-target_link_libraries(dbd-unlocker PRIVATE dbd-unlocker-warnings OpenSSL::SSL OpenSSL::Crypto nerutils wsock32 ws2_32 wininet crypt32 nlohmann_json)
+target_link_libraries(dbd-unlocker PRIVATE dbd-unlocker-warnings OpenSSL::SSL OpenSSL::Crypto nerutils wsock32 ws2_32 wininet crypt32 nlohmann_json zlib)
 
 if(NOT MSVC)
     target_link_options(dbd-unlocker PRIVATE -static -static-libgcc -static-libstdc++)
diff --git a/vendor/CMakeLists.txt b/vendor/CMakeLists.txt
index ea6c5a5..fdea3f8 100644
--- a/vendor/CMakeLists.txt
+++ b/vendor/CMakeLists.txt
@@ -1,2 +1,5 @@
 add_subdirectory(nerutils)
 add_subdirectory(json)
+
+set(ZLIB_BUILD_TESTING OFF)
+add_subdirectory(zlib)
diff --git a/vendor/zlib b/vendor/zlib
new file mode 160000
index 0000000..f9dd600
--- /dev/null
+++ b/vendor/zlib
@@ -0,0 +1 @@
+Subproject commit f9dd6009be3ed32415edf1e89d1bc38380ecb95d